1. Field of the Invention
The present invention relates to a QoS-guaranteed video stream method and system, and a transmitting server, and more particularly, to a QoS-guaranteed video stream method and system, and a transmitting server capable of guaranteeing QoS in a scheme of providing a video stream by using a plurality of layers.
2. Description of the Related Art
Along with development of a mobile device and a mobile network, a mobile voice over internet protocol (VoIP) service, through which images are exchanged between a plurality of users in real time by using a mobile device, is getting popular. Further, a real time streaming service such as a professional baseball game live broadcast in a mobile device is also getting popular.
A scalable video codec (SVC) may be user to transmit a video stream to a plurality of users. A scalable video codec such as H.264 SVC may form one video stream with a plurality of layers so as to be transmitted.
According to the technology of providing a video stream by using a SVC, a transmitting server transmits one video stream to a relay server, and a plurality of user terminals connect to the relay server and receive the video stream.
The technology of providing a video stream by using a SVC according to a conventional art transmits a video stream which is optimized in a network situation between a transmitting server and a relay server. Hence, the image quality of the layer received by the user terminal may provide only a scheme of selecting one layer from among video streams having the image quality for each defined layer based on the network situation between the transmitting server and the relay server. That is, there is a limit that the network state between the user terminal and the relay server does not affect the quality of the video stream which is transmitted by the transmitting server.